Which of the following s-block element form oxide and nitride when treated with air?

1 K

2 Na

3 Mg

4 Rb

Which of the following can't exist?

1 LiCl.2H₂O

2 MgCl₂.6H₂O

3 [Al(H₂O)₆]³⁺

4 [BeF₆]^4-

Select the incorrect statement (s)

1 Li and Mg have widely different properties

2 NaHCO₃ and LiHCO₃ are solid compounds

3 Stability of hydrides follows the order LiH$>$NaH$>$KH

4 Both 1 & 2

Which of the following carbonate is sparingly soluble in water?

1 Li₂CO₃

2 Na₂CO₃

3 K₂CO₃

4 Rb₂CO₃

The rate of setting of plaster of Paris is enhanced and retarded respectively by-

1. Alum, sodium chloride

2. Borax, alum

3. Sodium chloride, alum

4. Alum, borax

X$\underset{△}{\overset{N_2}{\to }}$Y$\underset{}{\overset{H_{2}O}{\to }}$ Z (Colourless gas). Z gives blue colour solution with CuSO₄ and X does not give flame test. X,Y and Z respectively are

1 Ca, Ca(OH)₂, H₂

2 Mg, Mg₃N₂, NH₃

3 Na, Na₃N, NH₃

4 Ba, Ba(NO₃)₂, H₂

When CO₂ is passed through brine solution, saturated with ammonia, white crystals precipitate out. The crystals are of

1. NH₄HCO₃

2. NH₄Cl

3. Na₂CO₃

4. NaHCO₃

The property of group 2 elements that increases with increase in their atomic number-

1. Solubility of their sulphates

2. Thermal stability of carbonates

3. Solubility of their carbonates

4. Electronegativity and ionisation energy

The incorrect reaction for thermal decomposition among the following is

1 2NaNO₃$\stackrel{△}{\to }$2NaNO₂+O₂

2 NH₄NO₂$\stackrel{△}{\to }$N₂+2H₂O

3 4LiNO_{3$\stackrel{△}{\to }$}2Li₂O+4NO₂+O₂

4 Na₂CO₃$\underset{temperature}{\overset{Low}{\to }}$ Na₂O+CO₂

The incorrect statement among following is-